Japan finds plutonium in soil at nuke plant

Tokyo, March 29, 2011

Plutonium found in soil at the Fukushima nuclear complex heightened alarm on Tuesday over Japan's battle to contain the world's worst atomic crisis in 25 years, while opposition MPs attacked the prime minister for his handling of the disaster.

Some opposition lawmakers lambasted Naoto Kan in parliament for not extending an evacuation zone around the plant. Kan said he was seeking advice on widening the area, which would force 130,000 people to move in addition to 70,000 already displaced.

Plant operator Tokyo Electric Power Co said plutonium was found at low-risk levels in five places at the facility, which was crippled by a massive earthquake and tsunami on March 11.

A by-product of atomic reactions and also used in nuclear bombs, plutonium is highly carcinogenic and one of the most dangerous substances on the planet, experts say.

They believe some of the plutonium may have come from spent fuel rods at Fukushima or damage to reactor No. 3, the only one to use plutonium in its fuel mix.

Japan's Nuclear and Industrial Safety Agency said while the plutonium levels were not harmful to human health, the discovery could mean a breach in the reactor's containment mechanism.

"Plutonium is a substance that's emitted when the temperature is high, and it's also heavy and so does not leak out easily," agency deputy director Hidehiko Nishiyama told a news conference.

"So if plutonium has emerged from the reactor, that tells us something about the damage to the fuel. And if it has breached the original containment system, it underlines the gravity and seriousness of this accident.”

Sakae Muto, a Tokyo Electric vice-president, said the traces of plutonium-238, 239 and 240 were in keeping with levels found in Japan in the past due to particles in the atmosphere from nuclear testing abroad. "I apologise for making people worried," Muto said.

Partial meltdown

Workers at Fukushima may have to struggle for weeks or months under extremely dangerous conditions to re-start cooling systems vital to control the reactors and avert total meltdown.

On Monday, highly contaminated water was found in concrete tunnels extending beyond one reactor, while at the weekend radiation hit 100,000 times over normal in water inside another.

That poses a major dilemma for Tokyo Electric, which wants to douse the reactors to cool them, but not worsen the radiation spread, Chief Cabinet Secretary Yukio Edano said on Tuesday.

"On the issue of pumping in water, we must avoid a situation in which the temperature (of the fuel rods) rises and the water boils off. So this cooling is a priority. On the other hand, on the standing water, under the circumstances work must proceed to remove it as quickly as possible," he said.

The crisis, the worst nuclear accident since Chernobyl in 1986, has contaminated vegetables and milk from the area, as well as the surrounding sea. US experts said groundwater, reservoirs and the sea all faced "significant contamination".

Facing a long and uncertain operation, Tokyo Electric has sought help from firms including Electricite de France and Areva, the French government said.

Japan is also consulting Washington. The head of the US Nuclear Regulatory Commission, Gregory Jaczko, met Japanese officials in Tokyo on Monday.

"The unprecedented challenge before us remains serious and our best experts remain fully engaged to help Japan address the situation," Jaczko said in a statement.

Experts have said the lack of information and some inconsistent data makes it hard to understand what is happening at Fukushima, which appears to have moved from a core-meltdown phase to one in which management of released radioactivity is paramount.

"There's a lot of radioactivity outside the containment barriers that poses a threat to workers and the public that needs to be addressed," said David Lochbaum, director of the nuclear safety project at the US-based Union of Concerned Scientists, a long-time nuclear watchdog group. "That's the top priority." – Reuters